Story at a glance

  • A new study used models of sea-level rise and patterns of migration and population to predict which areas of the country will be most affected in the future.
  • While coastal areas are most directly affected by sea-level rise, many inland areas of the country will see the effects in the form of increased populations.
  • The Rocky Mountains and surrounding areas will be least affected by both sea-level rise and resulting migration.

Global sea levels are rising by about one-eighth of an inch each year, and that rate continues to increase. And if you think you won't be affected because you live further inland, think again. 

A new study uses data from the National Oceanic and Atmospheric Administration (NOAA), U.S. Census and the Internal Revenue Service to predict migration patterns in the U.S. if sea levels continue to rise. The model considers the affects of climate change on sea-level rise, urban heat islands, population, median income and demographics to determine what areas would be directly and indirectly affected.  

“As oceans expand and encroach into previously habitable land, affected people — climate migrants — will move towards locations further inland, looking for food and shelter in areas that are less susceptible to increased flooding or extreme weather events,” the study says. 

If you live in a coastal area marked in blue on the model, chances are that your neighborhood will be either partially or fully flooded as the sea level continues to rise. When this happens, other areas, marked in shades of purple on the model, will see an indirect effect in the form of migrants. 

The East Coast, which has larger coastal population centers and shallower coastlines, will be more affected — especially in the Southeast. The study names New Orleans and Miami as two of the most vulnerable populations due to coastal flooding. Where will they end up? The study predicts southern Mississippi and southeastern Georgia will see large numbers of migrants in comparison to their relatively small populations. 

Researchers calculated the number of additional migrants due to sea-level rise as a percentage of each county's population, modeling the indirect effect of sea-level rise on a local level. Areas with a greater percentage of projected migrants out of their total population are marked in darker shades of purple than those with lesser percentages. This matters, the study’s authors say, because those areas may not be prepared to handle a sudden influx of migrants. 

“In general, we find that previously ‘unpopular’ migrant destinations — areas with relatively low numbers of incoming migrants — would be more popular solely due to their close proximity to counties that experience ‘direct effects,’” they say. 

But the results of the model are very uncertain, says Caleb Robinson, one of the study's authors. The predictions for sea-level rise and other components each come with their own level of uncertainty, which are compounded in the final findings. Don't start packing your bags yet, but maybe keep an eye on the shoreline. 

Published on Feb 06, 2020